Frankly I can't remember what they could do with pools in Sims 2 enough to compare.
I like that they can sit at the edge of the pool and talk to each other with their feet dangling in here in this iteration. I like that they can talk to each other while treading water and of course splash. I love the pool death sink it's pretty scary looking actually.
I agree we need more pool stuff and some more water interactions though. I'd love them to add a freestyle swim stroke especially. I think more will come eventually. Can't say I'm bored with it all though. They can take their time getting to that in my opinion.